The sacro-iliac joint is a diarthrodial joint that joins the sacrum to the ilium bones of the pelvis. In the sacro-iliac joint, the sacral surface has hyaline cartilage that moves against fibrocartilage of the iliac surface. The spinal column is configured so that the weight of an upper body rests on the sacro-iliac joints at the juncture of the sacrum and ilia. Stress placed on the sacro-iliac joints in an upright position of the body makes the lower back susceptible to injury.
Disorders of the sacro-iliac joint can cause low back and radiating buttock and leg pain in patients suffering from degeneration and laxity of the sacro-iliac joint. In some cases, the sacro-iliac joint can undergo dehydration and destabilization, similar to other cartilaginous joints, which causes significant pain. The sacro-iliac joint is also susceptible to trauma and degeneration, from fracture and instability. It is estimated that disorders of the sacro-iliac joint are a source of pain for millions of people suffering from back and radicular symptoms.
Non-surgical treatments, such as medication, injection, mobilization, rehabilitation and exercise can be effective, however, may fail to relieve the symptoms associated with these disorders. Surgical treatment of these disorders includes stabilization and/or arthrodesis. Stabilization can include the use of bone screws that are directly threaded into bone. Arthrodesis may include immobilization of a joint. The present disclosure describes an improvement over these prior art technologies.